That’s a strange one……. I would expect your coach to have some sort of multi-camera switcher, with the output of that switcher going to the Pioneer (three cameras into the switcher, one signal out of the switcher – going to the Pioneer). I am not aware of any switchers that could generate such a message or that would not allow use while moving forward. I would expect that sort of message to come from the Pioneer unit, but how would it know which camera is being sent to it from the switcher?...... Why would the Pioneer allow you to see the output of the switch box when the side cameras are selected, but not show it when the rear camera is selected by the switcher.
Can you verify that that my assumption regarding your setup is correct?...... Do all three of your cameras go to a switcher box? Or, does the rear camera go directly to the Pioneer and the side cameras go to the switch box (and then on to a second a/v input on the Pioneer)?
